A station (STA) on a WLAN shares an operating channel used by an access point (AP) for the WLAN with other stations. In present WLANs, packets are not identified as retransmitted packets, including aggregated packets that may include a mixture of original, first sent packets and retransmitted packets aggregated together. A station must decode a payload of a packet in order to determine whether the packet is addressed to the particular station rather than to another station that shares the same WLAN. A presently proposed 802.11ax Wi-Fi packet structure includes a field for the packet that identifies the recipient station address to which the packet is intended, but does not indicate a transmitting station address from which the packet originates. Instead, transmit and receive addresses and a retransmission bit are included in a medium access control (MAC) header, which cannot be confirmed until the MAC header and the payload are decoded and the frame check sequence (FCS) that accompanies the MAC header and payload combination is checked. When the FCS passes, the payload can be accepted, and retransmission is not required. When the FCS fails, the MAC header and/or the payload may be in error, and present implementations drop the payload entirely.
H-ARQ is used in cellular wireless communication systems that include dedicated control signaling channels separate from data channels, unlike in WLAN systems, in which a shared communication channel is used to communicate data packets and accompanying control information between the AP and multiple STAs.